In a conventional vehicle anti-collision system, an object detecting device which detects positions of other vehicles has been employed to avoid collision with another vehicle such as a preceding vehicle or an oncoming vehicle. As such an object detecting device, there is a device which detects an object by recognition processing of sensor fusion where a detection result by a radar is combined with an image captured by a camera.
Although the width of a target object to be detected cannot be calculated in principle by a radar, information of the distance to the object can be acquired. On the other hand, although the distance to the target object cannot be acquired by a monocular camera, the width of the object can be detected. Sensor fusion is a method which combines the functions of a plurality of sensors to detect an object. Detecting an object by using sensor fusion has been considered in various ways.
For example, patent literature 1 describes a method of processing an image captured by a camera through the use of the detection result by a radar to recognize and detect preceding vehicles and the like from the distance measured by the radar and vehicle characteristic quantity (car width, etc.) acquired by the image processing.